A low-cost spatial contrast sensitivity display driver

The circuit described here can provide the line and frame signals to drive anx, y display scope or oscilloscope at high resolution (1,000 lines) and repetition rate (50 Hz). Synchronizing circuitry at the input of the circuit allows the raster scan to be locked to an input signal, such as the square-wave output from a function generator, while another waveform from the same function genera-tor, the sine output, drives the z (intensity) input of the display scope. A stable spatial contrast display results. Spatial contrast depth is a direct function of z input modulation voltage. Spatial frequency is a direct function of the function generator frequency. The circuit can be used with a programmable function generator under computer control.